Electrical furnace for treating ores



A. couNAs. ELECTRICAL FURNACE FOR TREATING GRES.

APPLICTION FILED AUG. 2l

' 920' Patented 0t.3,1922,

3 SHEETS*SHEET l.

A. COUNAS. ELECTRICAL FURNACE FOR TREATING GRES.

APPLICATION FILED AuG.2I. 1920.

PIIIenIeII 0015.3,19'21 3 SHEETS-SHEET 2.

A. couNAs. ELECTRICAL FURNACE FOR TREATING ORES.

APPLICATION FILED AUG-2l, 1920. 1,430,948, Patented oet. 3,1922.

3 SHEETS-SHEET 3.-

Patented Oei. 3, 1922. j i

UNITED` STATES PATENT OFFICE.

Ae-AMEMNON coUNAs, or raars, FRANCE.

ELECTRICAL EUENACE Een rml-:Arme onEs.

Application filed. August 21, 1920.- Serial lNo. 405,127.

y ythe following is a complete specification.

This invention relates to an electric furnace for treating-in the electric furnace, ores, such as lead, Zinc, copper or other oresl The treatment ofthe ores, particularly the lead ores is carrie-d out in the majority of the processes at present in use, in air blast waterjackets, by carrying out first of all a preliminary roasting, which even inthe `majority of `cases has to be effected in such a way that the lead lore treated in the furn nace only retains a very small quantity (2 to v3 per cent for example) of sulphur, in orderf to obviate the formation of matte of i lead retaining a large quantity of lead. The

mel-ting of the ore is effected after 4this double roasting in furnaces other than ele`c` out it being necessary to subjectthem'to a preliminary roasting and enables both the temperature of the furnace and the position of the Zone of maximum temperature to be regulated so as to render the fusion of the metals possible while only permitting of the volatilization thereof when that is advantageous to the operation.` v

` In the accompanying drawing, various constructional forms of an electric furnace are illustrated.

Fig. 1 is an elevation of kthe furnace, half in section.

Fig. 2 is a sectional plan thereof through the hopper and through the upper part of the heating chamber of the furnace.

Fig. 3 shows a modification.

This furnace comprises a lower part or Vat a, surmounted by a charging hopper Y) of convenient height, having a breadth less` than that of the vat a and extending throughout the entire length of the furnace ductor of electricitysuch as retort carbon forl instance, forming the terminal for the re turn of the current, thecurrent being ad mitted through electrodes al, c each of which consists of .a block of material such as carbon extending into the vat a inside a water jacket f andmounted on a rod g supported by a suitable frame it. The upper end of each rod g is screw-threadedas shown in Figure l, and supports a nut j the yperiphery of which has teeth in gear with a pinion k provided with a hand operated device, en-

varied at will. In this way it is possible to abling the extent to which thek electrodes `project intoy the interior of they vat a to be regulate the distance of each of the electrodes d e from the central return terminal c, so as to regulate at will the temperature of the furnace and the position of the Zone of fusion In consequence of the particular'arrangement of the charging hopper' b the vapours that are liberated during the'treatment of lead ores inside the vat a come into contact with the material to be treated contained in the hopper b and condense upon contact with the said material, owing to the arrangement of the medial return electrode c, which concentrates the heat towards the middle of the furnace and facilitates the rise of the fumes in the hopper.` p

furnace, so that in this way it is possible to4 i Vary at will the power of the furnace by suitably increasing the number of electrodes, the length of the furnace varying at the same time and in the same direction.

The operation is as follows: The roasted ores are introduced into the vat a by causing them to enter the `hopper' o, and then the current is passed through the electrodes al, e, thereby producing in the interior of the vat an appropriate temperature, concentrated on the central part c of the said vat so that vapours liberated come and condense immediately upon contact with the cold part of `the charge which is still contained in the hopper Z9. In consequence of this arrangement losses by volatilization are almost completely eliminated.

The arrangement described makes it possible, b'y suitably varying the position of the electrodes d, c in relation to one another andl to the return terminal c, to regulate the p0- sition of the are, and consequently to determine With precision the temperature of Working of the furnace as Well as the location Where the temperature is to be highest.

For the case of the utilization of the furnace according to the invention for the concentration of ores poor in Zinc, oxydized or sulphurous, a slightly different construe tional form of the furnace is used, Which is shown in Figure 3.

In this constructional form the hopper has at its base a suitable number of apertures m, which may be distributed over the four faces of the hopper, or only over tWo opposite faces, each of the apertures being adapted to receive a plug, preferably of a refractory material, not shown. In this case a fan or other suitable suction device is arranged outside the hopper, exerting suction in the said hopper through a large aperture n for example arrangedat one of the ends. The hopper is kept completely free and the speed of Working of the fan is so adjusted as to pass through the apertures m, a quantity of air suitable for the treatment to be effected.

During the Working of the furnace, the fan bein0f in operation, the hopper is thus converted into a chamber for the combustion of the fumes liberated by the ore or of the volatilized metals, thereby enabling the furnace to be utilized as a combustion and enriching chamber.

lVhat I claim is:

l. An electric furnace for treating ores, comprising a rectangular vat, a charging hopper above the vat, inclined electrodes on each side of the hopper and extending into the vat the number of the said electrodes being determined by the length of the said vat, and a return electrode forming part of the earth of the furnace, and arranged directly below the hopper.

2. An electric furnace for treating ores, comprising a rectangular vat, a charging hopper above the vat, inclined electrodes on each side of the hopper and extending into the vat, the number of the said electrodes being determined by the length of the said vat, the said electrodes surrounded each by a waterejacket, being arranged close to both the hopper and the Wall of the vat, thus taking off any vault, and a return electrode forming part of the hearth of the furnace, and arranged directly below the hopper.

3. An electric furnace for treating ores, comprising a vat having an electrode at its bottom, a charging hopper arranged above the vat directly over the said electrode, said hopper being provided at its base with openings in two ofits sides and With a large opening in one side adjacent its upper end, and electrodes on each side of the hopper and extending into the vat.

In testimony whereof I have hereunto set my hand at Paris this 26th da of Jul 1920.

AGAMEMNONy COU AS. 

